Styrene-based thermoplastic elastomer composites without tiger-stripe pattern and their preparation method

Abstract

This application provides a styrene-based thermoplastic elastomer composite material without tiger-skin pattern, comprising the following components in parts by weight: 90-99 parts of thermoplastic elastomer material; 1-10 parts of tiger-skin pattern eliminator; wherein the thermoplastic elastomer material comprises the following components in parts by weight: 13-44 parts of styrene-based thermoplastic elastomer, 20-65 parts of filler oil, 5-23 parts of polypropylene, 0-40 parts of inorganic filler, and 0-1 parts of additives; the tiger-skin pattern eliminator is one or more of vinyl or propylene-based materials, wherein the vinyl material has a melt index of 0.1-5 g / 10 min at 190°C and 2.16 kg, and the propylene-based material has a melt index of 0.1-10 g / 10 min at 230°C and 2.16 kg. Furthermore, this application also provides a method for preparing the styrene-based thermoplastic elastomer composite material without tiger-skin pattern.

Description

Technical Field

[0001] This application relates to the field of polymer material modification and processing technology, and in particular to a styrene-based thermoplastic elastomer composite material without tiger stripe pattern and its preparation method. Background Technology

[0002] Styrene-based thermoplastic elastomers are triblock polymers. The two ends are polystyrene, which acts as physical crosslinking points at room temperature, providing strength. The middle block is amorphous or microcrystalline polybutadiene and / or polyisoprene, or their hydrogenated derivatives, providing elasticity. Styrene-based thermoplastic elastomers typically cannot be used alone and require the addition of filler oils and polypropylene to improve their processing properties. For multi-component blends, differences in polarity, solubility parameters, and rheological properties between components can affect their compatibility. This can lead to unstable, serpentine flow of the blend melt between the front and back walls of the mold during injection molding, especially when producing large, thin-walled products. This results in a tiger-skin pattern, causing appearance defects.

[0003] In existing technologies, there are few studies on improving the tiger-stripe defect in styrene-based thermoplastic elastomer composites, and the methods usually involve adding high-flow polypropylene to the composite system to improve flowability and thus eliminate the tiger-stripe effect, which is a limited approach. Therefore, providing another technical solution that can effectively improve the tiger-stripe effect in styrene-based thermoplastic elastomer composites has significant research value and application potential. Summary of the Invention

[0004] To address the aforementioned issues, this application provides a styrene-based thermoplastic elastomer composite material without tiger-skin pattern.

[0005] In addition, this application also needs to provide a method for preparing the above-mentioned styrene-based thermoplastic elastomer composite material without tiger stripe pattern.

[0006] One embodiment of this application provides a styrene-based thermoplastic elastomer composite material without tiger-skin pattern, comprising the following components in parts by weight:

[0007] 90-99 parts of thermoplastic elastomer material,

[0008] Tiger-skin pattern remover: 1-10 parts;

[0009] The thermoplastic elastomer material comprises the following components in parts by weight:

[0010] 13–44 parts of styrene-based thermoplastic elastomers,

[0011] 20-65 parts of filler oil,

[0012] Polypropylene 5-23 parts,

[0013] Inorganic filler 0-40 parts,

[0014] 0-1 part of auxiliary agent;

[0015] The tiger-skin pattern remover is one or more of vinyl or acrylic materials. The vinyl material has a melt index of 0.1 to 5 g / 10 min at 190°C and 2.16 kg, and the acrylic material has a melt index of 0.1 to 10 g / 10 min at 230°C and 2.16 kg.

[0016] This application also provides a method for preparing the above-mentioned styrene-based thermoplastic elastomer composite material without tiger-stripe pattern, comprising the following steps:

[0017] Styrene-based thermoplastic elastomers and filler oils are stirred and mixed evenly to obtain the first mixture;

[0018] Polypropylene, inorganic filler, additives and tiger stripe removal agent are stirred and mixed evenly to obtain a second mixture;

[0019] The first mixture and the second mixture were successively added to a twin-screw extruder for melting, extrusion, and granulation to obtain a styrene-based thermoplastic elastomer composite material without tiger-skin pattern.

[0020] Compared with the prior art, the beneficial effects of this application are:

[0021] This application modifies styrene-based thermoplastic elastomers by selecting vinyl or propylene-based materials with low melt flow index as tiger-skin pattern eliminaters. The resulting styrene-based thermoplastic elastomer composite material is free of tiger-skin patterns and has high shear viscosity and low gloss, making it widely applicable to automotive interior and exterior parts. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a twin-screw extruder screw assembly provided in an embodiment of this application.

[0023] Figure 2 for Figure 1 The diagram shows a three-dimensional structure of the cam-mixing element.

[0024] Figure 3 for Figure 1 The diagram shows a three-dimensional structure of the distributed mixing element.

[0025] Figures 4A to 4C This is a schematic diagram of tiger stripe grading provided in an embodiment of this application, wherein... Figure 4A Corresponding to tiger stripe level 1, Figure 4B Corresponding to tiger stripe level 2, Figure 4C This corresponds to level 3 tiger stripe pattern.

[0026] Explanation of main component symbols

[0027] Twin-screw extruder screw assembly 100

[0028] barrel 10

[0029] First feeding port 11

[0030] Second feeding port 12

[0031] Screw 20

[0032] First conveying element 21

[0033] Toothed hybrid element 22

[0034] Cam Hybrid Element 23

[0035] Arc-shaped groove 231

[0036] convex edge 232

[0037] Second conveying element 24

[0038] Distributed hybrid element 25

[0039] Spiral 251

[0040] 252 screw groove

[0041] Pin 253 Detailed Implementation

[0042] The present application is further illustrated below with reference to embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions in the art or as recommended by the manufacturer; the raw materials and reagents used, unless otherwise specified, are all commercially available from the conventional market. Any non-substantial changes and substitutions made by those skilled in the art based on this application are within the scope of protection claimed in this application.

[0043] One embodiment of this application provides a styrene-based thermoplastic elastomer composite material without tiger-skin pattern, comprising the following components in parts by weight:

[0044] 90-99 parts of thermoplastic elastomer material,

[0045] Tiger-skin pattern remover: 1-10 parts;

[0046] The thermoplastic elastomer material comprises the following components in parts by weight:

[0047] 13–44 parts of styrene-based thermoplastic elastomers,

[0048] 20-65 parts of filler oil,

[0049] Polypropylene 5-23 parts,

[0050] Inorganic filler 0-40 parts,

[0051] 0-1 part of auxiliary agent;

[0052] The tiger-skin pattern remover is one or more of vinyl or propylene materials. The vinyl material has a melt index of 0.1 to 5 g / 10 min at 190°C and 2.16 kg, and the propylene material has a melt index of 0.1 to 10 g / 10 min at 230°C and 2.16 kg.

[0053] Research has found that the formation of tiger stripes in styrene-based thermoplastic elastomer composite systems requires two necessary conditions: (1) unstable serpentine flow, which is mainly caused by poor compatibility between the components in the material system. The factors affecting compatibility include differences in polarity, solubility, and rheology between the components; (2) the serpentine flow causes inconsistent shear rates on the mold wall and its corresponding positions (reflected on the upper and lower surfaces at the same position on the injection molded product), resulting in inconsistent deformation of the melt of low volume content components (volume fraction less than 50%, because inorganic fillers are rigid and do not have viscoelasticity, the volume fraction referred to here is the volume fraction occupied by each polymer component after removing inorganic fillers) (non-continuous "island" phase) (essentially caused by the viscoelasticity of polymer melt), resulting in the formation of tiger stripes. Bright stripes are generated at the mold wall where the melt front flows serpentinely (the velocity gradient is large here, the shear rate is large, resulting in large deformation of low content components), and dark stripes are generated at the corresponding position (opposite mold wall) (the velocity gradient is small here, the shear rate is small, and the deformation of low content components is small). Even if the material exhibits unstable serpentine flow during injection molding, tiger-skin patterns will not be produced if the melt deformation of the mold wall and the corresponding low-content components is consistent. In other words, tiger-skin patterns will only be produced if two necessary conditions are met simultaneously.

[0054] This application selects a tiger-stripe eliminator with a low melt index. By improving the elasticity of the viscoelasticity of the low-content component melt, the low-content component melt undergoes less deformation during injection molding, thereby effectively eliminating tiger-stripe patterns. Furthermore, the vinyl materials, propylene-based materials, and soft blocks of styrene-based thermoplastic elastomers (i.e., hydrogenated polybutadiene or (and) hydrogenated polyisoprene), filler oils, and polypropylene used as tiger-stripe eliminators in this application have similar chemical structures. Therefore, they have similar solubility parameters and good compatibility, which can further suppress the formation of tiger-stripe patterns.

[0055] Furthermore, using high-flow polypropylene to eliminate tiger-stripe patterns results in a composite material with excessively low melt shear viscosity, leading to a high gloss level (for appearance parts, a matte finish is typically required) and making it prone to defects such as flash and surface pits. This application avoids these defects by using low-flow propylene-based materials and / or vinyl materials.

[0056] In this embodiment, the styrene-based thermoplastic elastomer is selected from one or more of styrene-ethylene / butene-styrene block copolymers, styrene-ethylene / propylene-styrene block copolymers, and styrene-ethylene-ethylene / propylene-styrene block copolymers.

[0057] The styrene-based thermoplastic elastomer (TPS) selected in this application does not contain double bonds, and has better weather resistance and mechanical properties compared to unhydrogenated SBS or SIS.

[0058] Furthermore, the styrene content in the styrene-based thermoplastic elastomer is 10–60 wt%.

[0059] When the styrene content of a styrene-based thermoplastic elastomer is less than 10 wt%, its tensile strength is low; when the styrene content is greater than 60 wt%, the elasticity of the material almost disappears. Therefore, in this invention, a styrene-based thermoplastic elastomer with a styrene content of 10–60 wt% is selected as the matrix resin. Thus, to achieve a balance between tensile strength and elasticity, the selected styrene-based thermoplastic elastomer has a styrene content of 10–60 wt%.

[0060] Furthermore, the styrene-based thermoplastic elastomer has a linear or star-shaped structure, wherein the number-average molecular weight of the linear styrene-based thermoplastic elastomer is 100,000–300,000 g / mol, and the number-average molecular weight of the star-shaped styrene-based thermoplastic elastomer is 200,000–400,000 g / mol. ① Lower molecular weight styrene-based thermoplastic elastomers (50,000–100,000 g / mol for linear structures and 80,000–200,000 g / mol for star structures) have lower tensile strength, and products made using them as blend components have a glossy surface; ② Styrene-based thermoplastic elastomers with a linear molecular weight of 100,000–300,000 g / mol and a star-shaped molecular weight of 200,000–400,000 g / mol have better mechanical properties, and products made using them as blend components have a matte surface, which is desirable; ③ For the same molecular weight, the star structure has better flowability than the linear structure.

[0061] In this embodiment, the melt index of the polypropylene at 230°C and 2.16 kg is 15-100 g / 10 min.

[0062] Polypropylene and styrene-based thermoplastic elastomers have good compatibility. The addition of polypropylene: ① improves the processability of the material of this invention; ② regulates hardness and mechanical properties. The melt index of polypropylene is selected as 15–100 g / 10 min (2.16 kg, 230 °C). The reason for selecting this melt index is that a melt index less than 15 g / 10 min is incompatible with the rheology of the material of this invention, resulting in poor compatibility and deteriorated mechanical properties; a melt index greater than 100 g / 10 min results in a brighter surface in blends made with polypropylene as a component, but also lower tensile strength.

[0063] In this embodiment, the vinyl material is one or more of high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), or ethylene-alpha olefin copolymer (POE).

[0064] In this embodiment, the propylene-based material is one or more of homopolymer polypropylene, random copolymer polypropylene, or propylene-based elastomer.

[0065] Here, vinyl materials refer to polymers with an ethylene monomer content greater than 50 mol%, and propylene-based materials refer to polymers with a propylene monomer content greater than 50 mol%. This application selects specific types of vinyl materials and / or propylene-based materials with specific melt index ranges, which have good compatibility with polypropylene (i.e., the low-content component) in the composite material system. This improves the viscoelasticity of the polypropylene component melt in the blend of this invention, thereby reducing deformation of the polypropylene component melt during injection molding and eliminating the formation of tiger-skin patterns.

[0066] In this embodiment, the filler oil is any one or both of cycloalkane oil and straight-chain alkane oil; the inorganic filler is any one or both of calcium carbonate and talc.

[0067] Among them, cycloalkane oils or straight-chain alkane oils have excellent compatibility with styrene-based thermoplastic elastomers and can improve the thermoplastic processing performance of styrene-based thermoplastic elastomers. Inorganic fillers can reduce costs and improve the dimensional stability of composite materials.

[0068] In this embodiment, the additive is one or more of antioxidants, light stabilizers, ultraviolet light absorbers, or lubricants.

[0069] Further, the antioxidant is any one or two of hindered phenolic antioxidants and phosphite antioxidants; the light stabilizer is a hindered amine light stabilizer; the ultraviolet light absorber is a benzotriazole ultraviolet light absorber; and the lubricant is any one or a combination of two or more of oleamide, erucamide, ethylene bisoleamide, ethylene bisstearamide, polyethylene wax, or polydimethylsiloxane.

[0070] This application also provides a method for preparing the above-mentioned styrene-based thermoplastic elastomer composite material, comprising the following steps:

[0071] Styrene-based thermoplastic elastomers and filler oils are stirred and mixed evenly to obtain the first mixture;

[0072] Polypropylene, inorganic filler, additives and tiger stripe removal agent are stirred and mixed evenly to obtain a second mixture;

[0073] The first mixture and the second mixture were successively added to a twin-screw extruder for melting, extrusion, and granulation to obtain a styrene-based thermoplastic elastomer composite material without tiger-skin pattern.

[0074] Please see Figure 1 , Figure 2 and Figure 3 In this embodiment, the twin-screw extruder used includes a specific twin-screw extruder screw assembly 100. The twin-screw extruder screw assembly 100 includes a barrel 10 and two screws 20 disposed within the barrel 10, the two screws 20 meshing with each other. The screws 20 are provided axially in sequence with a first conveying element 21, a toothed mixing element 22, a cam mixing element 23, a second conveying element 24, and a distribution mixing element 25.

[0075] The cam mixing element 23 includes three spaced-apart protrusions 232, with an arc-shaped groove 231 formed between every two adjacent protrusions 232. The protrusions 232 and the arc-shaped grooves 231 together form a three-cam structure. The distribution mixing element 25 includes a helical ridge 251, with helical grooves 252 between the helical ridges 251. The helical grooves 252 are uniformly provided with rhomboid pins 253.

[0076] The barrel 10 is provided with a first feeding port 11 and a second feeding port 12. The first feeding port 11 is provided corresponding to the first conveying element 21, and the second feeding port 12 is provided corresponding to the second conveying element 24.

[0077] During the preparation process, the first mixture is added through the first feed port 11, and the second mixture is added through the second feed port 12. Styrene-based thermoplastic elastomers and filler oils enter the first conveying element 21 and are forcibly conveyed to the toothed mixing element 22 and the cam mixing element 23, where they are fully plasticized to form a uniform and stable rubber mixture, creating a "sea" structure. Polypropylene and other materials are granular and easily absorbed; they are added to the second conveying element 24 and mixed with the first mixture. After passing through the distribution mixing element 25 with diamond-shaped pins 253, each diamond pin 253 splits the flow into two streams. Through multiple splitting processes, the granules are fully plasticized and distributed throughout the rubber body, forming a uniform "island" structure. This results in a "sea-island" structure, with polyolefins uniformly distributed in the rubber melt, ensuring the full performance of each component and further reducing the formation of tiger-skin patterns in the final composite material.

[0078] The following specific embodiments provide a detailed description of the tiger-skin pattern-free styrene-based thermoplastic elastomer composite material and its preparation method.

[0079] The raw materials used in the various embodiments and comparative examples of this invention are described below:

[0080] I. Thermoplastic Elastomers

[0081] 1. Styrene-based thermoplastic elastomers

[0082] TPS-1: Kronen 1651, a linear styrene-ethylene / butene-styrene block copolymer with a styrene content of 33wt% and a number-average molecular weight of 220,000 g / mol;

[0083] TPS-2: Kronen 1654, a linear styrene-ethylene / butene-styrene block copolymer with a styrene content of 31 wt% and a number-average molecular weight of 180,000 g / mol;

[0084] TPS-3: Yuehua 602T, a star-shaped styrene-ethylene / butene-styrene block copolymer with a styrene content of 35wt% and a number-average molecular weight of 280,000g / mol;

[0085] TPS-4: Kronen 1633, a linear styrene-ethylene / butene-styrene block copolymer with a styrene content of 30wt% and a number-average molecular weight of 330,000g / mol;

[0086] TPS-5: Yuehua 604T, a star-shaped styrene-ethylene / butene-styrene block copolymer with a styrene content of 33wt% and a number-average molecular weight of 380,000g / mol;

[0087] TPS-6: Kuraray 4055, a linear styrene-ethylene-ethylene / propylene-styrene block copolymer with a styrene content of 31wt% and a number average molecular weight of 220,000g / mol.

[0088] 2. Filler oil

[0089] Oil-1: Karamay KN4010, cycloalkane oil;

[0090] Oil-2: SsangYong 250N from South Korea, a straight-chain alkane oil;

[0091] 3. Polypropylene

[0092] PP-1: Formosa Plastics 1600D, melt index is 60g / 10min (2.16kg, 230℃);

[0093] PP-2: Formosa Plastics 1124, melt index is 15g / 10min (2.16kg, 230℃);

[0094] 4. Inorganic fillers

[0095] FIL-1: Xufeng Calcium Carbonate NC-40;

[0096] FIL-2: Xufeng Talc Powder BHS-1250A;

[0097] 5. Additives

[0098] Antioxidant 1010: Antioxidant 168: UV770: UV-P: Erucamide = 1:2:2:3:2, all of which are commercially available.

[0099] II. Tiger Skin Stripe Eliminator

[0100] (1) Vinyl materials

[0101] 1. High-density polyethylene

[0102] HDPE-1: Formosa Plastics 8001, melt index is 0.1g / 10min (2.16kg, 190℃);

[0103] HDPE-2: Formosa Plastics 8010, melt index is 1g / 10min (2.16kg, 190℃);

[0104] HDPE-3: Formosa Plastics 8040, melt index is 4g / 10min (2.16kg, 190℃);

[0105] 2. Linear low-density polyethylene

[0106] LLDPE-1: Formosa Plastics 3210, melt index is 1g / 10min (2.16kg, 190℃);

[0107] LLDPE-2: Formosa Plastics 3220, melt index is 2g / 10min (2.16kg, 190℃);

[0108] LLDPE-3: Formosa Plastics 3840, melt index is 5g / 10min (2.16kg, 190℃);

[0109] 3. Ethylene-α-olefin copolymer

[0110] POE-1: DOW Engage HM7387, melt index 0.3 g / 10 min (2.16 kg, 190 °C);

[0111] POE-2: DOW Engage 8107, melt index 1 g / 10 min (2.16 kg, 190 °C);

[0112] POE-3: DOW Engage 8207, melt index 5 g / 10 min (2.16 kg, 190 °C);

[0113] (2) Propylene-based materials

[0114] 1. Homopolymer polypropylene

[0115] HOPP-1: Formosa Plastics 1005, melt index is 0.5g / 10min (2.16kg, 230℃);

[0116] HOPP-2: Formosa Plastics 1040, melt index is 5g / 10min (2.16kg, 230℃);

[0117] HOPP-3: Formosa Plastics 1080, melt index is 10g / 10min (2.16kg, 230℃);

[0118] 2. Random copolymer polypropylene

[0119] COPP-1: Formosa Plastics 5003, melt index 0.25g / 10min (2.16kg, 230℃);

[0120] COPP-2: Formosa Plastics 5018, melt index is 1.7g / 10min (2.16kg, 230℃);

[0121] COPP-3: Formosa Plastics 5060, melt index is 7g / 10min (2.16kg, 230℃);

[0122] 3. Propylene-based elastomers

[0123] V-1: ExxonMobil Vistamaxx 6102, melt index 3g / 10min (2.16kg, 230℃);

[0124] V-2: ExxonMobil Vistamaxx 3000, melt index 8 g / 10 min (2.16 kg, 230 °C);

[0125] 4. High-flowability polypropylene

[0126] HFPP: LyondellBasell MF650Y, melt index 1800g / 10min (2.16kg, 230℃).

[0127] The styrene-based thermoplastic elastomer composite materials in the embodiments and comparative examples of this application were prepared using the following process:

[0128] Weigh out the styrene-based thermoplastic elastomer, filler oil, polypropylene, inorganic filler, additives, and tiger-skin pattern remover according to the respective mass fractions in the examples and comparative examples. First, add the styrene-based thermoplastic elastomer and filler oil to a high-speed mixer and stir for 3 minutes to obtain the first mixture;

[0129] Polypropylene, inorganic filler, additives and tiger stripe removal agent are added to a high-speed mixer and stirred for 1 minute to obtain a second mixture. The speed of the high-speed mixer is 180 rpm.

[0130] The first mixture is fed into a twin-screw extruder through the first feed port, and the second mixture is fed into the twin-screw extruder through the second feed port. The mixture is then melted, extruded, and granulated to obtain a styrene-based thermoplastic elastomer composite material. The twin-screw extruder has a length-to-diameter ratio of 52:1 and a processing temperature of 160–250°C.

[0131] In each embodiment of this application, the styrene-based thermoplastic elastomer composite material was made into injection molded samples of uniform size. In this embodiment, the size of the injection molded sample was 140mm × 150mm × 2mm.

[0132] (1) Tiger stripe grade: Grade 1 is invisible to the naked eye, uniform and without stripes (see Figure 4A Grade 2 is slightly visible to the naked eye, with narrow and dense stripes (see...). Figure 4B Grade 3 is clearly visible to the naked eye, with wide stripes (see...). Figure 4C ).

[0133] Five people were selected to rate the tiger stripe pattern of each injection molded sample, and the average value was taken. When the tiger stripe pattern level was ≤1.5, it was defined as no tiger stripe pattern.

[0134] (2) Shear viscosity: Tested according to ASTM D3835-2016 standard, the test temperature was 200℃, and the shear rate was 11170 / s;

[0135] (3) Gloss: Tested according to ASTM D523 standard, with a test angle of 60°.

[0136] First, this application provides a series of thermoplastic elastomer materials (TPEs), the formulations of which and the corresponding tiger stripe grades are shown in Table 1.

[0137] Table 1. Components (parts) and properties of thermoplastic elastomer materials

[0138]

[0139] This embodiment provides a series of styrene-based thermoplastic elastomer composite materials without tiger stripe pattern, and their formulation components (parts) and tiger stripe pattern grade parameters are shown in Table 2.

[0140] Table 2. Components (parts) and tiger stripe grades of Examples 1-45

[0141]

[0142]

[0143]

[0144]

[0145]

[0146] As can be seen from Tables 1 and 2, in Examples 1 to 45, using vinyl or propylene-based materials as tiger-skin stripe eliminators can achieve a tiger-skin stripe grade of ≤1.5 in styrene-based thermoplastic elastomer composites. In contrast, in TPE-1 to TPE-6 without tiger-skin stripe eliminators, the tiger-skin stripe grade is ≥2. This indicates that the tiger-skin stripe eliminator in this application can significantly improve the appearance of styrene-based thermoplastic elastomer composites and eliminate tiger-skin stripes.

[0147] TPE-6 without tiger stripe removal agent was used as Comparative Example 1, and TPE-6 with high-flow polypropylene HFPP was used as Comparative Example 2. The performance of the three was compared with that of Example 20. The formulation and performance parameters are shown in Table 3.

[0148] Table 3 Comparison of components and performance between Comparative Examples 1-2 and Example 20

[0149]

[0150] As can be seen from Table 3, in Comparative Example 2, high-flow-rate polypropylene (melt index of 1800 g / 10 min) was added to a styrene-based thermoplastic elastomer. Although it could eliminate the tiger-skin pattern, the shear viscosity was too low, which easily led to appearance defects such as flash and surface pits. Moreover, the surface gloss was high. In contrast, in Example 20, while eliminating the tiger-skin pattern, the shear viscosity was high, and the gloss was much lower than that of Comparative Example 2.

[0151] In summary, this application demonstrates that by adding vinyl or propylene-based materials with low melt flow index as tiger-stripe eliminateants to styrene-based thermoplastic elastomers, the appearance of styrene-based thermoplastic elastomer composites can be significantly improved, resulting in tiger-stripe-free styrene-based thermoplastic elastomer composites. Furthermore, the prepared styrene-based thermoplastic elastomer composites exhibit high shear viscosity and low gloss. These styrene-based thermoplastic elastomer composites can be widely used in automotive interior parts.

[0152] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application.

Claims

1. A styrene-based thermoplastic elastomer composite material without tiger-stripe pattern, characterized in that, The components include the following parts by weight: 90-99 parts of thermoplastic elastomer material, Tiger stripe removal agent 1-10 parts; The thermoplastic elastomer material comprises the following components in parts by weight: 35-44 parts of styrene-based thermoplastic elastomer, Filler oil 20-65 parts, Polypropylene 5-23 parts, Inorganic filler 0~40 parts, 0-1 part of auxiliary agent; The tiger-skin pattern remover is one or more of vinyl or acrylic materials. The vinyl material has a melt index of 0.1~5 g / 10 min at 190℃ and 2.16 kg, and the acrylic material has a melt index of 5~10 g / 10 min at 230℃ and 2.16 kg. The styrene content in the styrene-based thermoplastic elastomer is 10~60 wt%; The styrene-based thermoplastic elastomer has a linear or star-shaped structure, wherein the number-average molecular weight of the linear styrene-based thermoplastic elastomer is 100,000 to 300,000 g / mol, and the number-average molecular weight of the star-shaped styrene-based thermoplastic elastomer is 200,000 to 400,000 g / mol.

2. The styrene-based thermoplastic elastomer composite material without tiger-stripe pattern as described in claim 1, characterized in that, The styrene-based thermoplastic elastomer is selected from one or more of styrene-ethylene / butene-styrene block copolymers, styrene-ethylene / propylene-styrene block copolymers, and styrene-ethylene-ethylene / propylene-styrene block copolymers.

3. The styrene-based thermoplastic elastomer composite material without tiger-stripe pattern as described in claim 1, characterized in that, The polypropylene has a melt index of 15~100g / 10min at 230℃ and 2.16kg.

4. The styrene-based thermoplastic elastomer composite material without tiger-stripe pattern as described in claim 1, characterized in that, The vinyl material is one or more of high-density polyethylene, linear low-density polyethylene, or ethylene-α-olefin copolymer.

5. The styrene-based thermoplastic elastomer composite material without tiger-stripe pattern as described in claim 1, characterized in that, The propylene-based material is one or more of homopolymer polypropylene, random copolymer polypropylene, or propylene-based elastomer.

6. The styrene-based thermoplastic elastomer composite material without tiger-stripe pattern as described in claim 1, characterized in that, The filler oil is one or both of cycloalkane oil and straight-chain alkane oil; the inorganic filler is one or both of calcium carbonate and talc.

7. The styrene-based thermoplastic elastomer composite material without tiger-stripe pattern as described in claim 1, characterized in that, The additive is one or more of antioxidants, light stabilizers, ultraviolet light absorbers, or lubricants.

8. A method for preparing a styrene-based thermoplastic elastomer composite material without tiger-skin pattern as described in any one of claims 1 to 7, characterized in that, Includes the following steps: Styrene-based thermoplastic elastomers and filler oils are stirred and mixed evenly to obtain the first mixture; Polypropylene, inorganic filler, additives and tiger stripe removal agent are stirred and mixed evenly to obtain a second mixture; The first mixture and the second mixture were successively added into a twin-screw extruder for melting, extrusion, and granulation to obtain a styrene-based thermoplastic elastomer composite material without tiger-skin pattern. The twin-screw extruder includes a barrel and two screws disposed inside the barrel, the two screws meshing with each other; The screw is provided with a first conveying element, a first toothed mixing element, a cam mixing element, a second toothed mixing element, a second conveying element, and a distribution mixing element in sequence along the axial direction; wherein, the distribution mixing element is provided with a pin; The barrel is provided with a first feeding port and a second feeding port, the first feeding port being configured to correspond to the first conveying element and the second feeding port being configured to correspond to the second conveying element; The preparation method further includes the steps of: adding the first mixture through the first feeding port; and The second mixture is added through the second feed port.

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